1 /*------------------------------------------------------------------------
3 SDCCralloc.c - source file for register allocation. (8051) specific
5 Written By - Sandeep Dutta . sandeep.dutta@usa.net (1998)
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 In other words, you are welcome to use, share and improve this program.
22 You are forbidden to forbid anyone else to use, share and improve
23 what you give them. Help stamp out software-hoarding!
24 -------------------------------------------------------------------------*/
30 /*-----------------------------------------------------------------*/
31 /* At this point we start getting processor specific although */
32 /* some routines are non-processor specific & can be reused when */
33 /* targetting other processors. The decision for this will have */
34 /* to be made on a routine by routine basis */
35 /* routines used to pack registers are most definitely not reusable */
36 /* since the pack the registers depending strictly on the MCU */
37 /*-----------------------------------------------------------------*/
47 bitVect *totRegAssigned; /* final set of LRs that got into registers */
50 bitVect *funcrUsed; /* registers used in a function */
56 /* Shared with gen.c */
57 int ds390_ptrRegReq; /* one byte pointer register required */
63 {REG_GPR, R2_IDX, REG_GPR, "r2", "ar2", "0", 2, 1, 1},
64 {REG_GPR, R3_IDX, REG_GPR, "r3", "ar3", "0", 3, 1, 1},
65 {REG_GPR, R4_IDX, REG_GPR, "r4", "ar4", "0", 4, 1, 1},
66 {REG_GPR, R5_IDX, REG_GPR, "r5", "ar5", "0", 5, 1, 1},
67 {REG_GPR, R6_IDX, REG_GPR, "r6", "ar6", "0", 6, 1, 1},
68 {REG_GPR, R7_IDX, REG_GPR, "r7", "ar7", "0", 7, 1, 1},
69 {REG_PTR, R0_IDX, REG_PTR, "r0", "ar0", "0", 0, 1, 1},
70 {REG_PTR, R1_IDX, REG_PTR, "r1", "ar1", "0", 1, 1, 1},
71 {REG_GPR, DPL_IDX, REG_GPR, "dpl", "dpl", "dpl", 0, 0, 0},
72 {REG_GPR, DPH_IDX, REG_GPR, "dph", "dph", "dph", 0, 0, 0},
73 {REG_GPR, DPX_IDX, REG_GPR, "dpx", "dpx", "dpx", 0, 0, 0},
74 {REG_GPR, B_IDX, REG_GPR, "b", "b", "b", 0, 0, 0},
75 {REG_GPR, X8_IDX, REG_GPR, "x8", "x8", "xreg", 0, 0, 0},
76 {REG_GPR, X9_IDX, REG_GPR, "x9", "x9", "xreg", 1, 0, 0},
77 {REG_GPR, X10_IDX, REG_GPR, "x10", "x10", "xreg", 2, 0, 0},
78 {REG_GPR, X11_IDX, REG_GPR, "x11", "x11", "xreg", 3, 0, 0},
79 {REG_GPR, X12_IDX, REG_GPR, "x12", "x12", "xreg", 4, 0, 0},
80 {REG_CND, CND_IDX, REG_GPR, "C", "psw", "xreg", 0, 0, 0},
81 {0, DPL1_IDX, 0, "dpl1", "dpl1", "dpl1", 0, 0, 0},
82 {0, DPH1_IDX, 0, "dph1", "dph1", "dph1", 0, 0, 0},
83 {0, DPX1_IDX, 0, "dpx1", "dpx1", "dpx1", 0, 0, 0},
84 {0, DPS_IDX, 0, "dps", "dps", "dps", 0, 0, 0},
85 {0, A_IDX, 0, "a", "acc", "acc", 0, 0, 0},
86 {0, AP_IDX, 0, "ap", "ap", "ap", 0, 0, 0},
89 static void spillThis (symbol *);
90 static void freeAllRegs ();
91 static iCode * packRegsDPTRuse (operand *);
92 static int packRegsDPTRnuse (operand *,int);
94 /*-----------------------------------------------------------------*/
95 /* allocReg - allocates register of given type */
96 /*-----------------------------------------------------------------*/
102 for (i = 0; i < ds390_nRegs; i++)
105 /* if type is given as 0 then any
106 free register will do */
110 regs390[i].isFree = 0;
113 bitVectSetBit (currFunc->regsUsed, i);
116 /* other wise look for specific type
118 if (regs390[i].isFree &&
119 regs390[i].type == type)
121 regs390[i].isFree = 0;
124 bitVectSetBit (currFunc->regsUsed, i);
131 /*-----------------------------------------------------------------*/
132 /* ds390_regWithIdx - returns pointer to register wit index number */
133 /*-----------------------------------------------------------------*/
135 ds390_regWithIdx (int idx)
139 for (i = 0; i < sizeof(regs390)/sizeof(regs); i++)
140 if (regs390[i].rIdx == idx)
143 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
144 "regWithIdx not found");
148 /*-----------------------------------------------------------------*/
149 /* freeReg - frees a register */
150 /*-----------------------------------------------------------------*/
157 /*-----------------------------------------------------------------*/
158 /* useReg - marks a register as used */
159 /*-----------------------------------------------------------------*/
167 /*-----------------------------------------------------------------*/
168 /* nFreeRegs - returns number of free registers */
169 /*-----------------------------------------------------------------*/
176 for (i = 0; i < ds390_nRegs; i++)
177 if (regs390[i].isFree && regs390[i].type == type)
182 /*-----------------------------------------------------------------*/
183 /* nfreeRegsType - free registers with type */
184 /*-----------------------------------------------------------------*/
186 nfreeRegsType (int type)
191 if ((nfr = nFreeRegs (type)) == 0)
192 return nFreeRegs (REG_GPR);
195 return nFreeRegs (type);
200 /*-----------------------------------------------------------------*/
201 /* isOperandInReg - returns true if operand is currently in regs */
202 /*-----------------------------------------------------------------*/
203 static int isOperandInReg(operand *op)
205 if (!IS_SYMOP(op)) return 0;
206 if (OP_SYMBOL(op)->ruonly) return 1;
207 if (OP_SYMBOL(op)->accuse) return 1;
208 if (OP_SYMBOL(op)->dptr) return 1;
209 return bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(op)->key);
212 /*-----------------------------------------------------------------*/
213 /* computeSpillable - given a point find the spillable live ranges */
214 /*-----------------------------------------------------------------*/
216 computeSpillable (iCode * ic)
220 /* spillable live ranges are those that are live at this
221 point . the following categories need to be subtracted
223 a) - those that are already spilt
224 b) - if being used by this one
225 c) - defined by this one */
227 spillable = bitVectCopy (ic->rlive);
229 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
231 bitVectCplAnd (spillable, ic->uses); /* used in this one */
232 bitVectUnSetBit (spillable, ic->defKey);
233 spillable = bitVectIntersect (spillable, _G.regAssigned);
238 /*-----------------------------------------------------------------*/
239 /* noSpilLoc - return true if a variable has no spil location */
240 /*-----------------------------------------------------------------*/
242 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
244 return (sym->usl.spillLoc ? 0 : 1);
247 /*-----------------------------------------------------------------*/
248 /* hasSpilLoc - will return 1 if the symbol has spil location */
249 /*-----------------------------------------------------------------*/
251 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
253 return (sym->usl.spillLoc ? 1 : 0);
256 /*-----------------------------------------------------------------*/
257 /* directSpilLoc - will return 1 if the splilocation is in direct */
258 /*-----------------------------------------------------------------*/
260 directSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
262 if (sym->usl.spillLoc &&
263 (IN_DIRSPACE (SPEC_OCLS (sym->usl.spillLoc->etype))))
269 /*-----------------------------------------------------------------*/
270 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
271 /* but is not used as a pointer */
272 /*-----------------------------------------------------------------*/
274 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
276 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
279 /*-----------------------------------------------------------------*/
280 /* rematable - will return 1 if the remat flag is set */
281 /*-----------------------------------------------------------------*/
283 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
288 /*-----------------------------------------------------------------*/
289 /* notUsedInRemaining - not used or defined in remain of the block */
290 /*-----------------------------------------------------------------*/
292 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
294 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
295 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
298 /*-----------------------------------------------------------------*/
299 /* allLRs - return true for all */
300 /*-----------------------------------------------------------------*/
302 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
307 /*-----------------------------------------------------------------*/
308 /* liveRangesWith - applies function to a given set of live range */
309 /*-----------------------------------------------------------------*/
311 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
312 eBBlock * ebp, iCode * ic)
317 if (!lrs || !lrs->size)
320 for (i = 1; i < lrs->size; i++)
323 if (!bitVectBitValue (lrs, i))
326 /* if we don't find it in the live range
327 hash table we are in serious trouble */
328 if (!(sym = hTabItemWithKey (liveRanges, i)))
330 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
331 "liveRangesWith could not find liveRange");
335 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
336 addSetHead (&rset, sym);
343 /*-----------------------------------------------------------------*/
344 /* leastUsedLR - given a set determines which is the least used */
345 /*-----------------------------------------------------------------*/
347 leastUsedLR (set * sset)
349 symbol *sym = NULL, *lsym = NULL;
351 sym = lsym = setFirstItem (sset);
356 for (; lsym; lsym = setNextItem (sset))
359 /* if usage is the same then prefer
360 the spill the smaller of the two */
361 if (lsym->used == sym->used)
362 if (getSize (lsym->type) < getSize (sym->type))
366 if (lsym->used < sym->used)
371 setToNull ((void *) &sset);
376 /*-----------------------------------------------------------------*/
377 /* noOverLap - will iterate through the list looking for over lap */
378 /*-----------------------------------------------------------------*/
380 noOverLap (set * itmpStack, symbol * fsym)
384 for (sym = setFirstItem (itmpStack); sym;
385 sym = setNextItem (itmpStack))
387 if (bitVectBitValue(sym->clashes,fsym->key)) return 0;
392 /*-----------------------------------------------------------------*/
393 /* isFree - will return 1 if the a free spil location is found */
394 /*-----------------------------------------------------------------*/
399 V_ARG (symbol **, sloc);
400 V_ARG (symbol *, fsym);
402 /* if already found */
406 /* if it is free && and the itmp assigned to
407 this does not have any overlapping live ranges
408 with the one currently being assigned and
409 the size can be accomodated */
411 noOverLap (sym->usl.itmpStack, fsym) &&
412 getSize (sym->type) >= getSize (fsym->type))
421 /*-----------------------------------------------------------------*/
422 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
423 /*-----------------------------------------------------------------*/
425 spillLRWithPtrReg (symbol * forSym)
431 if (!_G.regAssigned ||
432 bitVectIsZero (_G.regAssigned))
435 r0 = ds390_regWithIdx (R0_IDX);
436 r1 = ds390_regWithIdx (R1_IDX);
438 /* for all live ranges */
439 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
440 lrsym = hTabNextItem (liveRanges, &k))
444 /* if no registers assigned to it or
446 /* if it does not overlap with this then
447 not need to spill it */
449 if (lrsym->isspilt || !lrsym->nRegs ||
450 (lrsym->liveTo < forSym->liveFrom))
453 /* go thru the registers : if it is either
454 r0 or r1 then spil it */
455 for (j = 0; j < lrsym->nRegs; j++)
456 if (lrsym->regs[j] == r0 ||
457 lrsym->regs[j] == r1)
466 /*-----------------------------------------------------------------*/
467 /* createStackSpil - create a location on the stack to spil */
468 /*-----------------------------------------------------------------*/
470 createStackSpil (symbol * sym)
473 int useXstack, model, noOverlay;
477 /* first go try and find a free one that is already
478 existing on the stack */
479 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
481 /* found a free one : just update & return */
482 sym->usl.spillLoc = sloc;
485 addSetHead (&sloc->usl.itmpStack, sym);
489 /* could not then have to create one , this is the hard part
490 we need to allocate this on the stack : this is really a
491 hack!! but cannot think of anything better at this time */
493 if (SNPRINTF (slocBuffer, sizeof(slocBuffer),
494 "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
496 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
501 sloc = newiTemp (slocBuffer);
503 /* set the type to the spilling symbol */
504 sloc->type = copyLinkChain (sym->type);
505 sloc->etype = getSpec (sloc->type);
506 if (options.model == MODEL_SMALL) {
507 SPEC_SCLS (sloc->etype) = S_DATA;
509 SPEC_SCLS (sloc->etype) = S_XDATA;
511 SPEC_EXTR (sloc->etype) = 0;
512 SPEC_STAT (sloc->etype) = 0;
513 SPEC_VOLATILE(sloc->etype) = 0;
514 SPEC_ABSA(sloc->etype) = 0;
516 /* we don't allow it to be allocated`
517 onto the external stack since : so we
518 temporarily turn it off ; we also
519 turn off memory model to prevent
520 the spil from going to the external storage
521 and turn off overlaying
524 useXstack = options.useXstack;
525 model = options.model;
526 noOverlay = options.noOverlay;
527 options.noOverlay = 1;
529 /* options.model = options.useXstack = 0; */
533 options.useXstack = useXstack;
534 options.model = model;
535 options.noOverlay = noOverlay;
536 sloc->isref = 1; /* to prevent compiler warning */
538 /* if it is on the stack then update the stack */
539 if (IN_STACK (sloc->etype))
541 currFunc->stack += getSize (sloc->type);
542 _G.stackExtend += getSize (sloc->type);
545 _G.dataExtend += getSize (sloc->type);
547 /* add it to the _G.stackSpil set */
548 addSetHead (&_G.stackSpil, sloc);
549 sym->usl.spillLoc = sloc;
552 /* add it to the set of itempStack set
553 of the spill location */
554 addSetHead (&sloc->usl.itmpStack, sym);
558 /*-----------------------------------------------------------------*/
559 /* isSpiltOnStack - returns true if the spil location is on stack */
560 /*-----------------------------------------------------------------*/
562 isSpiltOnStack (symbol * sym)
572 /* if (sym->_G.stackSpil) */
575 if (!sym->usl.spillLoc)
578 etype = getSpec (sym->usl.spillLoc->type);
579 if (IN_STACK (etype))
585 /*-----------------------------------------------------------------*/
586 /* spillThis - spils a specific operand */
587 /*-----------------------------------------------------------------*/
589 spillThis (symbol * sym)
592 /* if this is rematerializable or has a spillLocation
593 we are okay, else we need to create a spillLocation
595 if (!(sym->remat || sym->usl.spillLoc))
596 createStackSpil (sym);
599 /* mark it has spilt & put it in the spilt set */
600 sym->isspilt = sym->spillA = 1;
601 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
603 bitVectUnSetBit (_G.regAssigned, sym->key);
604 bitVectUnSetBit (_G.totRegAssigned, sym->key);
606 for (i = 0; i < sym->nRegs; i++)
610 freeReg (sym->regs[i]);
614 /* if spilt on stack then free up r0 & r1
615 if they could have been assigned to some
617 if (!ds390_ptrRegReq && isSpiltOnStack (sym) && !options.stack10bit)
620 spillLRWithPtrReg (sym);
623 if (sym->usl.spillLoc && !sym->remat)
624 sym->usl.spillLoc->allocreq++;
628 /*-----------------------------------------------------------------*/
629 /* selectSpil - select a iTemp to spil : rather a simple procedure */
630 /*-----------------------------------------------------------------*/
632 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
634 bitVect *lrcs = NULL;
638 /* get the spillable live ranges */
639 lrcs = computeSpillable (ic);
641 /* get all live ranges that are rematerizable */
642 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
645 /* return the least used of these */
646 return leastUsedLR (selectS);
649 /* get live ranges with spillLocations in direct space */
650 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
652 sym = leastUsedLR (selectS);
653 strncpyz (sym->rname,
654 sym->usl.spillLoc->rname[0] ?
655 sym->usl.spillLoc->rname : sym->usl.spillLoc->name,
658 /* mark it as allocation required */
659 sym->usl.spillLoc->allocreq++;
663 /* if the symbol is local to the block then */
664 if (forSym->liveTo < ebp->lSeq)
667 /* check if there are any live ranges allocated
668 to registers that are not used in this block */
669 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
671 sym = leastUsedLR (selectS);
672 /* if this is not rematerializable */
681 /* check if there are any live ranges that not
682 used in the remainder of the block */
683 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
685 sym = leastUsedLR (selectS);
698 /* find live ranges with spillocation && not used as pointers */
699 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
702 sym = leastUsedLR (selectS);
703 /* mark this as allocation required */
704 sym->usl.spillLoc->allocreq++;
708 /* find live ranges with spillocation */
709 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
712 sym = leastUsedLR (selectS);
713 sym->usl.spillLoc->allocreq++;
717 /* couldn't find then we need to create a spil
718 location on the stack , for which one? the least
720 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
723 /* return a created spil location */
724 sym = createStackSpil (leastUsedLR (selectS));
725 sym->usl.spillLoc->allocreq++;
729 /* this is an extreme situation we will spill
730 this one : happens very rarely but it does happen */
736 /*-----------------------------------------------------------------*/
737 /* spilSomething - spil some variable & mark registers as free */
738 /*-----------------------------------------------------------------*/
740 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
745 /* get something we can spil */
746 ssym = selectSpil (ic, ebp, forSym);
748 /* mark it as spilt */
749 ssym->isspilt = ssym->spillA = 1;
750 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
752 /* mark it as not register assigned &
753 take it away from the set */
754 bitVectUnSetBit (_G.regAssigned, ssym->key);
755 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
757 /* mark the registers as free */
758 for (i = 0; i < ssym->nRegs; i++)
760 freeReg (ssym->regs[i]);
762 /* if spilt on stack then free up r0 & r1
763 if they could have been assigned to as gprs */
764 if (!ds390_ptrRegReq && isSpiltOnStack (ssym) && !options.stack10bit)
767 spillLRWithPtrReg (ssym);
770 /* if this was a block level spil then insert push & pop
771 at the start & end of block respectively */
774 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
775 /* add push to the start of the block */
776 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
777 ebp->sch->next : ebp->sch));
778 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
779 /* add pop to the end of the block */
780 addiCodeToeBBlock (ebp, nic, NULL);
783 /* if spilt because not used in the remainder of the
784 block then add a push before this instruction and
785 a pop at the end of the block */
786 if (ssym->remainSpil)
789 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
790 /* add push just before this instruction */
791 addiCodeToeBBlock (ebp, nic, ic);
793 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
794 /* add pop to the end of the block */
795 addiCodeToeBBlock (ebp, nic, NULL);
804 /*-----------------------------------------------------------------*/
805 /* getRegPtr - will try for PTR if not a GPR type if not spil */
806 /*-----------------------------------------------------------------*/
808 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
814 /* try for a ptr type */
815 if ((reg = allocReg (REG_PTR)))
818 /* try for gpr type */
819 if ((reg = allocReg (REG_GPR)))
822 /* we have to spil */
823 if (!spilSomething (ic, ebp, sym))
826 /* make sure partially assigned registers aren't reused */
827 for (j=0; j<=sym->nRegs; j++)
829 sym->regs[j]->isFree = 0;
831 /* this looks like an infinite loop but
832 in really selectSpil will abort */
836 /*-----------------------------------------------------------------*/
837 /* getRegGpr - will try for GPR if not spil */
838 /*-----------------------------------------------------------------*/
840 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
846 /* try for gpr type */
847 if ((reg = allocReg (REG_GPR)))
850 if (!ds390_ptrRegReq)
851 if ((reg = allocReg (REG_PTR)))
854 /* we have to spil */
855 if (!spilSomething (ic, ebp, sym))
858 /* make sure partially assigned registers aren't reused */
859 for (j=0; j<=sym->nRegs; j++)
861 sym->regs[j]->isFree = 0;
863 /* this looks like an infinite loop but
864 in really selectSpil will abort */
868 /*-----------------------------------------------------------------*/
869 /* getRegPtrNoSpil - get it cannot split */
870 /*-----------------------------------------------------------------*/
871 static regs *getRegPtrNoSpil()
875 /* try for a ptr type */
876 if ((reg = allocReg (REG_PTR)))
879 /* try for gpr type */
880 if ((reg = allocReg (REG_GPR)))
885 /* just to make the compiler happy */
889 /*-----------------------------------------------------------------*/
890 /* getRegGprNoSpil - get it cannot split */
891 /*-----------------------------------------------------------------*/
892 static regs *getRegGprNoSpil()
896 if ((reg = allocReg (REG_GPR)))
899 if (!ds390_ptrRegReq)
900 if ((reg = allocReg (REG_PTR)))
905 /* just to make the compiler happy */
909 /*-----------------------------------------------------------------*/
910 /* symHasReg - symbol has a given register */
911 /*-----------------------------------------------------------------*/
913 symHasReg (symbol * sym, regs * reg)
917 for (i = 0; i < sym->nRegs; i++)
918 if (sym->regs[i] == reg)
924 /*-----------------------------------------------------------------*/
925 /* deassignLRs - check the live to and if they have registers & are */
926 /* not spilt then free up the registers */
927 /*-----------------------------------------------------------------*/
929 deassignLRs (iCode * ic, eBBlock * ebp)
935 for (sym = hTabFirstItem (liveRanges, &k); sym;
936 sym = hTabNextItem (liveRanges, &k))
940 /* if it does not end here */
941 if (sym->liveTo > ic->seq)
944 /* if it was spilt on stack then we can
945 mark the stack spil location as free */
950 sym->usl.spillLoc->isFree = 1;
956 if (!bitVectBitValue (_G.regAssigned, sym->key))
959 /* special case check if this is an IFX &
960 the privious one was a pop and the
961 previous one was not spilt then keep track
963 if (ic->op == IFX && ic->prev &&
964 ic->prev->op == IPOP &&
965 !ic->prev->parmPush &&
966 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
967 psym = OP_SYMBOL (IC_LEFT (ic->prev));
973 bitVectUnSetBit (_G.regAssigned, sym->key);
975 /* if the result of this one needs registers
976 and does not have it then assign it right
978 if (IC_RESULT (ic) &&
979 !(SKIP_IC2 (ic) || /* not a special icode */
980 ic->op == JUMPTABLE ||
986 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
987 result->liveTo > ic->seq && /* and will live beyond this */
988 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
989 result->regType == sym->regType && /* same register types */
990 result->nRegs && /* which needs registers */
991 !result->isspilt && /* and does not already have them */
993 !bitVectBitValue (_G.regAssigned, result->key) &&
994 /* the number of free regs + number of regs in this LR
995 can accomodate the what result Needs */
996 ((nfreeRegsType (result->regType) +
997 sym->nRegs) >= result->nRegs)
1001 for (i = 0; i < result->nRegs; i++)
1003 result->regs[i] = sym->regs[i];
1005 result->regs[i] = getRegGpr (ic, ebp, result);
1007 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
1008 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
1012 /* free the remaining */
1013 for (; i < sym->nRegs; i++)
1017 if (!symHasReg (psym, sym->regs[i]))
1018 freeReg (sym->regs[i]);
1021 freeReg (sym->regs[i]);
1028 /*-----------------------------------------------------------------*/
1029 /* reassignLR - reassign this to registers */
1030 /*-----------------------------------------------------------------*/
1032 reassignLR (operand * op)
1034 symbol *sym = OP_SYMBOL (op);
1037 /* not spilt any more */
1038 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1039 bitVectUnSetBit (_G.spiltSet, sym->key);
1041 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1042 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1046 for (i = 0; i < sym->nRegs; i++)
1047 sym->regs[i]->isFree = 0;
1050 /*-----------------------------------------------------------------*/
1051 /* willCauseSpill - determines if allocating will cause a spill */
1052 /*-----------------------------------------------------------------*/
1054 willCauseSpill (int nr, int rt)
1056 /* first check if there are any avlb registers
1057 of te type required */
1060 /* special case for pointer type
1061 if pointer type not avlb then
1062 check for type gpr */
1063 if (nFreeRegs (rt) >= nr)
1065 if (nFreeRegs (REG_GPR) >= nr)
1070 if (ds390_ptrRegReq)
1072 if (nFreeRegs (rt) >= nr)
1077 if (nFreeRegs (REG_PTR) +
1078 nFreeRegs (REG_GPR) >= nr)
1083 /* it will cause a spil */
1087 /*-----------------------------------------------------------------*/
1088 /* positionRegs - the allocator can allocate same registers to res- */
1089 /* ult and operand, if this happens make sure they are in the same */
1090 /* position as the operand otherwise chaos results */
1091 /*-----------------------------------------------------------------*/
1093 positionRegs (symbol * result, symbol * opsym)
1095 int count = min (result->nRegs, opsym->nRegs);
1096 int i, j = 0, shared = 0;
1099 /* if the result has been spilt then cannot share */
1104 /* first make sure that they actually share */
1105 for (i = 0; i < count; i++)
1107 for (j = 0; j < count; j++)
1109 if (result->regs[i] == opsym->regs[j] && i != j)
1119 regs *tmp = result->regs[i];
1120 result->regs[i] = result->regs[j];
1121 result->regs[j] = tmp;
1128 /*-----------------------------------------------------------------*/
1129 /* unusedLRS - returns a bitVector of liveranges not used in 'ebp' */
1130 /*-----------------------------------------------------------------*/
1131 bitVect *unusedLRs (eBBlock *ebp)
1133 bitVect *ret = NULL;
1137 if (!ebp) return NULL;
1138 for (sym = hTabFirstItem(liveRanges,&key); sym ;
1139 sym = hTabNextItem(liveRanges,&key)) {
1141 if (notUsedInBlock(sym,ebp,NULL)) {
1142 ret = bitVectSetBit(ret,sym->key);
1149 /*-----------------------------------------------------------------*/
1150 /* deassignUnsedLRs - if this baisc block ends in a return then */
1151 /* deassign symbols not used in this block */
1152 /*-----------------------------------------------------------------*/
1153 bitVect *deassignUnsedLRs(eBBlock *ebp)
1155 bitVect *unused = NULL;
1158 switch (returnAtEnd(ebp)) {
1159 case 2: /* successor block ends in a return */
1160 unused = unusedLRs((eBBlock *) setFirstItem(ebp->succList));
1162 case 1: /* this block ends in a return */
1163 unused = bitVectIntersect(unused,unusedLRs(ebp));
1168 for (i = 0 ; i < unused->size ; i++ ) {
1171 if (bitVectBitValue(unused,i)) {
1173 /* if assigned to registers */
1174 if (bitVectBitValue(_G.regAssigned,i)) {
1178 sym = hTabItemWithKey(liveRanges,i);
1179 /* remove it from regassigned & mark the
1181 bitVectUnSetBit(_G.regAssigned,i);
1182 for (j = 0 ; j < sym->nRegs; j++)
1183 freeReg(sym->regs[j]);
1185 /* not assigned to registers : remove from set*/
1186 bitVectUnSetBit(unused,i);
1194 /*-----------------------------------------------------------------*/
1195 /* reassignUnusedLRs - put registers to unused Live ranges */
1196 /*-----------------------------------------------------------------*/
1197 void reassignUnusedLRs (bitVect *unused)
1200 if (!unused) return ;
1202 for (i = 0 ; i < unused->size ; i++ ) {
1203 /* if unused : means it was assigned to registers before */
1204 if (bitVectBitValue(unused,i)) {
1208 /* put it back into reg set*/
1209 bitVectSetBit(_G.regAssigned,i) ;
1211 sym = hTabItemWithKey(liveRanges,i);
1212 /* makr registers busy */
1213 for (j = 0 ; j < sym->nRegs; j++)
1214 sym->regs[j]->isFree = 0;
1219 /*------------------------------------------------------------------*/
1220 /* verifyRegsAssigned - make sure an iTemp is properly initialized; */
1221 /* it should either have registers or have beed spilled. Otherwise, */
1222 /* there was an uninitialized variable, so just spill this to get */
1223 /* the operand in a valid state. */
1224 /*------------------------------------------------------------------*/
1226 verifyRegsAssigned (operand *op, iCode * ic)
1231 if (!IS_ITEMP (op)) return;
1233 sym = OP_SYMBOL (op);
1234 if (sym->isspilt) return;
1235 if (!sym->nRegs) return;
1236 if (sym->regs[0]) return;
1238 werrorfl (ic->filename, ic->lineno, W_LOCAL_NOINIT,
1239 sym->prereqv ? sym->prereqv->name : sym->name);
1244 /*-----------------------------------------------------------------*/
1245 /* serialRegAssign - serially allocate registers to the variables */
1246 /*-----------------------------------------------------------------*/
1248 serialRegAssign (eBBlock ** ebbs, int count)
1252 /* for all blocks */
1253 for (i = 0; i < count; i++)
1257 bitVect *unusedLRs = NULL;
1259 if (ebbs[i]->noPath &&
1260 (ebbs[i]->entryLabel != entryLabel &&
1261 ebbs[i]->entryLabel != returnLabel))
1264 unusedLRs = deassignUnsedLRs(ebbs[i]);
1266 /* of all instructions do */
1267 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1270 /* if this is an ipop that means some live
1271 range will have to be assigned again */
1273 reassignLR (IC_LEFT (ic));
1275 /* if result is present && is a true symbol */
1276 if (IC_RESULT (ic) && ic->op != IFX &&
1277 IS_TRUE_SYMOP (IC_RESULT (ic)))
1278 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1280 /* take away registers from live
1281 ranges that end at this instruction */
1282 deassignLRs (ic, ebbs[i]);
1284 /* some don't need registers */
1285 if (SKIP_IC2 (ic) ||
1286 ic->op == JUMPTABLE ||
1290 (IC_RESULT (ic) && POINTER_SET (ic)))
1293 /* now we need to allocate registers
1294 only for the result */
1297 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1303 /* if it does not need or is spilt
1304 or is already assigned to registers
1305 or will not live beyond this instructions */
1308 bitVectBitValue (_G.regAssigned, sym->key) ||
1309 sym->liveTo <= ic->seq)
1312 /* if some liverange has been spilt at the block level
1313 and this one live beyond this block then spil this
1315 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1320 /* if trying to allocate this will cause
1321 a spill and there is nothing to spill
1322 or this one is rematerializable then
1324 willCS = willCauseSpill (sym->nRegs, sym->regType);
1325 spillable = computeSpillable (ic);
1327 (willCS && bitVectIsZero (spillable)))
1335 /* if it has a spillocation & is used less than
1336 all other live ranges then spill this */
1338 if (sym->usl.spillLoc) {
1339 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1340 allLRs, ebbs[i], ic));
1341 if (leastUsed && leastUsed->used > sym->used) {
1346 /* if none of the liveRanges have a spillLocation then better
1347 to spill this one than anything else already assigned to registers */
1348 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1349 /* if this is local to this block then we might find a block spil */
1350 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1358 /* if we need ptr regs for the right side
1360 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1361 && getSize (OP_SYMBOL (IC_LEFT (ic))->type)
1362 <= (unsigned) PTRSIZE)
1367 /* else we assign registers to it */
1368 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1369 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1371 for (j = 0; j < sym->nRegs; j++)
1373 if (sym->regType == REG_PTR)
1374 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1376 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1378 /* if the allocation falied which means
1379 this was spilt then break */
1384 /* if it shares registers with operands make sure
1385 that they are in the same position */
1386 if (!POINTER_SET(ic) && !POINTER_GET(ic))
1388 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1389 OP_SYMBOL (IC_LEFT (ic))->nRegs)
1391 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1392 OP_SYMBOL (IC_LEFT (ic)));
1394 /* do the same for the right operand */
1395 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1396 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1398 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1399 OP_SYMBOL (IC_RIGHT (ic)));
1411 reassignUnusedLRs(unusedLRs);
1414 /* Check for and fix any problems with uninitialized operands */
1415 for (i = 0; i < count; i++)
1419 if (ebbs[i]->noPath &&
1420 (ebbs[i]->entryLabel != entryLabel &&
1421 ebbs[i]->entryLabel != returnLabel))
1424 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1431 verifyRegsAssigned (IC_COND (ic), ic);
1435 if (ic->op == JUMPTABLE)
1437 verifyRegsAssigned (IC_JTCOND (ic), ic);
1441 verifyRegsAssigned (IC_RESULT (ic), ic);
1442 verifyRegsAssigned (IC_LEFT (ic), ic);
1443 verifyRegsAssigned (IC_RIGHT (ic), ic);
1449 /*-----------------------------------------------------------------*/
1450 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1451 /*-----------------------------------------------------------------*/
1452 static void fillGaps()
1456 int loop = 0, change;
1459 if (getenv("DISABLE_FILL_GAPS")) return;
1461 /* First try to do DPTRuse once more since now we know what got into
1464 while (loop++ < 10) {
1467 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1468 sym = hTabNextItem(liveRanges,&key)) {
1469 int size = getSize(sym->type);
1471 if (sym->liveFrom == sym->liveTo) continue;
1473 if (sym->uptr && sym->dptr==0 && !sym->ruonly &&
1474 size < 4 && size > 1) {
1476 if (packRegsDPTRuse(operandFromSymbol(sym))) {
1478 /* if this was ssigned to registers then */
1479 if (bitVectBitValue(_G.totRegAssigned,sym->key)) {
1480 /* take it out of the register assigned set */
1481 bitVectUnSetBit(_G.totRegAssigned,sym->key);
1482 } else if (sym->usl.spillLoc) {
1483 sym->usl.spillLoc->allocreq--;
1484 sym->usl.spillLoc = NULL;
1488 sym->isspilt = sym->spillA = 0;
1492 /* try assigning other dptrs */
1493 if (sym->dptr == 0 && packRegsDPTRnuse(operandFromSymbol(sym),1) && !getenv("DPTRnDISABLE")) {
1494 /* if this was ssigned to registers then */
1495 if (bitVectBitValue(_G.totRegAssigned,sym->key)) {
1496 /* take it out of the register assigned set */
1497 bitVectUnSetBit(_G.totRegAssigned,sym->key);
1498 } else if (sym->usl.spillLoc) {
1499 sym->usl.spillLoc->allocreq--;
1500 sym->usl.spillLoc = NULL;
1503 sym->isspilt = sym->spillA = 0;
1508 /* look for livernages that was spilt by the allocator */
1509 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1510 sym = hTabNextItem(liveRanges,&key)) {
1515 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1516 if (!sym->uses || !sym->defs) continue ;
1517 /* find the liveRanges this one clashes with, that are
1518 still assigned to registers & mark the registers as used*/
1519 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1523 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1524 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1527 clr = hTabItemWithKey(liveRanges,i);
1530 /* mark these registers as used */
1531 for (k = 0 ; k < clr->nRegs ; k++ )
1532 useReg(clr->regs[k]);
1535 if (willCauseSpill(sym->nRegs,sym->regType)) {
1536 /* NOPE :( clear all registers & and continue */
1541 /* THERE IS HOPE !!!! */
1542 for (i=0; i < sym->nRegs ; i++ ) {
1543 if (sym->regType == REG_PTR)
1544 sym->regs[i] = getRegPtrNoSpil ();
1546 sym->regs[i] = getRegGprNoSpil ();
1549 /* For all its definitions check if the registers
1550 allocated needs positioning NOTE: we can position
1551 only ONCE if more than One positioning required
1553 We may need to perform the checks twice; once to
1554 position the registers as needed, the second to
1555 verify any register repositioning is still
1559 for (pass=0; pass<2; pass++) {
1560 for (i = 0 ; i < sym->defs->size ; i++ ) {
1561 if (bitVectBitValue(sym->defs,i)) {
1563 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1564 if (SKIP_IC(ic)) continue;
1565 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1566 /* if left is assigned to registers */
1567 if (IS_SYMOP(IC_LEFT(ic)) &&
1568 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1569 pdone += (positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)))>0);
1571 if (IS_SYMOP(IC_RIGHT(ic)) &&
1572 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1573 pdone += (positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)))>0);
1575 if (pdone > 1) break;
1578 for (i = 0 ; i < sym->uses->size ; i++ ) {
1579 if (bitVectBitValue(sym->uses,i)) {
1581 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1582 if (SKIP_IC(ic)) continue;
1583 if (POINTER_SET(ic) || POINTER_GET(ic)) continue ;
1585 /* if result is assigned to registers */
1586 if (IS_SYMOP(IC_RESULT(ic)) &&
1587 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1588 pdone += (positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)))>0);
1590 if (pdone > 1) break;
1593 if (pdone == 0) break; /* second pass only if regs repositioned */
1594 if (pdone > 1) break;
1596 /* had to position more than once GIVE UP */
1598 /* UNDO all the changes we made to try this */
1600 for (i=0; i < sym->nRegs ; i++ ) {
1601 sym->regs[i] = NULL;
1604 D (fprintf (stderr, "Fill Gap gave up due to positioning for "
1605 "%s in function %s\n",
1606 sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1609 D (fprintf (stderr, "FILLED GAP for %s in function %s\n",
1610 sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1611 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1612 sym->isspilt = sym->spillA = 0 ;
1613 sym->usl.spillLoc->allocreq--;
1614 sym->usl.spillLoc = NULL;
1622 /*-----------------------------------------------------------------*/
1623 /* rUmaskForOp :- returns register mask for an operand */
1624 /*-----------------------------------------------------------------*/
1626 ds390_rUmaskForOp (operand * op)
1632 /* only temporaries are assigned registers */
1636 sym = OP_SYMBOL (op);
1638 /* if spilt or no registers assigned to it
1640 if (sym->isspilt || !sym->nRegs)
1643 rumask = newBitVect (ds390_nRegs);
1645 for (j = 0; j < sym->nRegs; j++)
1647 rumask = bitVectSetBit (rumask,
1648 sym->regs[j]->rIdx);
1654 /*-----------------------------------------------------------------*/
1655 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1656 /*-----------------------------------------------------------------*/
1658 regsUsedIniCode (iCode * ic)
1660 bitVect *rmask = newBitVect (ds390_nRegs);
1662 /* do the special cases first */
1665 rmask = bitVectUnion (rmask,
1666 ds390_rUmaskForOp (IC_COND (ic)));
1670 /* for the jumptable */
1671 if (ic->op == JUMPTABLE)
1673 rmask = bitVectUnion (rmask,
1674 ds390_rUmaskForOp (IC_JTCOND (ic)));
1679 /* of all other cases */
1681 rmask = bitVectUnion (rmask,
1682 ds390_rUmaskForOp (IC_LEFT (ic)));
1686 rmask = bitVectUnion (rmask,
1687 ds390_rUmaskForOp (IC_RIGHT (ic)));
1690 rmask = bitVectUnion (rmask,
1691 ds390_rUmaskForOp (IC_RESULT (ic)));
1697 /*-----------------------------------------------------------------*/
1698 /* createRegMask - for each instruction will determine the regsUsed */
1699 /*-----------------------------------------------------------------*/
1701 createRegMask (eBBlock ** ebbs, int count)
1705 /* for all blocks */
1706 for (i = 0; i < count; i++)
1710 if (ebbs[i]->noPath &&
1711 (ebbs[i]->entryLabel != entryLabel &&
1712 ebbs[i]->entryLabel != returnLabel))
1715 /* for all instructions */
1716 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1721 if (SKIP_IC2 (ic) || !ic->rlive)
1724 /* first mark the registers used in this
1726 ic->rUsed = regsUsedIniCode (ic);
1727 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1729 /* now create the register mask for those
1730 registers that are in use : this is a
1731 super set of ic->rUsed */
1732 ic->rMask = newBitVect (ds390_nRegs + 1);
1734 /* for all live Ranges alive at this point */
1735 for (j = 1; j < ic->rlive->size; j++)
1740 /* if not alive then continue */
1741 if (!bitVectBitValue (ic->rlive, j))
1744 /* find the live range we are interested in */
1745 if (!(sym = hTabItemWithKey (liveRanges, j)))
1747 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1748 "createRegMask cannot find live range");
1752 /* special case for ruonly */
1753 if (sym->ruonly && sym->liveFrom != sym->liveTo) {
1754 int size = getSize(sym->type);
1756 for (k = 0 ; k < size; k++ )
1757 ic->rMask = bitVectSetBit (ic->rMask, j++);
1761 /* if no register assigned to it */
1762 if (!sym->nRegs || sym->isspilt)
1765 /* for all the registers allocated to it */
1766 for (k = 0; k < sym->nRegs; k++)
1769 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1775 /*-----------------------------------------------------------------*/
1776 /* rematStr - returns the rematerialized string for a remat var */
1777 /*-----------------------------------------------------------------*/
1779 rematStr (symbol * sym)
1782 iCode *ic = sym->rematiCode;
1789 /* if plus or minus print the right hand side */
1790 if (ic->op == '+' || ic->op == '-')
1792 SNPRINTF (s, sizeof(buffer) - strlen(buffer),
1793 "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1796 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1799 /* cast then continue */
1800 if (IS_CAST_ICODE(ic)) {
1801 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1804 /* we reached the end */
1805 SNPRINTF (s, sizeof(buffer) - strlen(buffer),
1806 "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1813 /*-----------------------------------------------------------------*/
1814 /* regTypeNum - computes the type & number of registers required */
1815 /*-----------------------------------------------------------------*/
1823 /* for each live range do */
1824 for (sym = hTabFirstItem (liveRanges, &k); sym;
1825 sym = hTabNextItem (liveRanges, &k))
1828 /* if used zero times then no registers needed */
1829 if ((sym->liveTo - sym->liveFrom) == 0)
1833 /* if the live range is a temporary */
1837 /* if the type is marked as a conditional */
1838 if (sym->regType == REG_CND)
1841 /* if used in return only then we don't
1843 if (sym->ruonly || sym->accuse)
1845 if (IS_AGGREGATE (sym->type) || sym->isptr)
1846 sym->type = aggrToPtr (sym->type, FALSE);
1850 /* if the symbol has only one definition &
1851 that definition is a get_pointer */
1852 if (bitVectnBitsOn (sym->defs) == 1 &&
1853 (ic = hTabItemWithKey (iCodehTab,
1854 bitVectFirstBit (sym->defs))) &&
1856 !IS_BITVAR (sym->etype) &&
1857 (aggrToPtrDclType (operandType (IC_LEFT (ic)), FALSE) == POINTER))
1860 if (ptrPseudoSymSafe (sym, ic))
1862 ptrPseudoSymConvert (sym, ic, rematStr (OP_SYMBOL (IC_LEFT (ic))));
1866 /* if in data space or idata space then try to
1867 allocate pointer register */
1871 /* if not then we require registers */
1872 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1873 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1874 getSize (sym->type));
1878 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1879 printTypeChain (sym->type, stderr);
1880 fprintf (stderr, "\n");
1883 /* determine the type of register required */
1884 if (sym->nRegs == 1 &&
1885 IS_PTR (sym->type) &&
1887 sym->regType = REG_PTR;
1889 sym->regType = REG_GPR;
1893 /* for the first run we don't provide */
1894 /* registers for true symbols we will */
1895 /* see how things go */
1901 /*-----------------------------------------------------------------*/
1902 /* freeAllRegs - mark all registers as free */
1903 /*-----------------------------------------------------------------*/
1909 for (i = 0; i < ds390_nRegs; i++)
1910 regs390[i].isFree = 1;
1913 /*-----------------------------------------------------------------*/
1914 /* deallocStackSpil - this will set the stack pointer back */
1915 /*-----------------------------------------------------------------*/
1917 DEFSETFUNC (deallocStackSpil)
1925 /*-----------------------------------------------------------------*/
1926 /* farSpacePackable - returns the packable icode for far variables */
1927 /*-----------------------------------------------------------------*/
1929 farSpacePackable (iCode * ic)
1933 /* go thru till we find a definition for the
1934 symbol on the right */
1935 for (dic = ic->prev; dic; dic = dic->prev)
1938 /* if the definition is a call then no */
1939 if ((dic->op == CALL || dic->op == PCALL) &&
1940 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1945 /* if shift by unknown amount then not */
1946 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1947 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1950 /* if pointer get and size > 1 */
1951 if (POINTER_GET (dic) &&
1952 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1955 if (POINTER_SET (dic) &&
1956 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1959 /* if any three is a true symbol in far space */
1960 if (IC_RESULT (dic) &&
1961 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1962 isOperandInFarSpace (IC_RESULT (dic)))
1965 if (IC_RIGHT (dic) &&
1966 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1967 isOperandInFarSpace (IC_RIGHT (dic)) &&
1968 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1971 if (IC_LEFT (dic) &&
1972 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1973 isOperandInFarSpace (IC_LEFT (dic)) &&
1974 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1977 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1979 if ((dic->op == LEFT_OP ||
1980 dic->op == RIGHT_OP ||
1982 IS_OP_LITERAL (IC_RIGHT (dic)))
1992 /*-----------------------------------------------------------------*/
1993 /* packRegsForAssign - register reduction for assignment */
1994 /*-----------------------------------------------------------------*/
1996 packRegsForAssign (iCode * ic, eBBlock * ebp)
2000 if (!IS_ITEMP (IC_RIGHT (ic)) ||
2001 OP_SYMBOL (IC_RIGHT (ic))->isind ||
2002 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
2007 /* if the true symbol is defined in far space or on stack
2008 then we should not since this will increase register pressure */
2010 if (isOperandInFarSpace (IC_RESULT (ic)))
2012 if ((dic = farSpacePackable (ic)))
2018 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
2023 /* find the definition of iTempNN scanning backwards if we find a
2024 a use of the true symbol in before we find the definition then
2026 for (dic = ic->prev; dic; dic = dic->prev)
2028 /* if there is a function call then don't pack it */
2029 if ((dic->op == CALL || dic->op == PCALL))
2038 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
2039 IS_OP_VOLATILE (IC_RESULT (dic)))
2045 if (IS_SYMOP (IC_RESULT (dic)) &&
2046 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
2048 if (POINTER_SET (dic))
2054 if (IS_SYMOP (IC_RIGHT (dic)) &&
2055 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
2056 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
2062 if (IS_SYMOP (IC_LEFT (dic)) &&
2063 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
2064 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
2070 if (POINTER_SET (dic) &&
2071 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
2079 return 0; /* did not find */
2081 /* if the result is on stack or iaccess then it must be
2082 the same atleast one of the operands */
2083 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
2084 OP_SYMBOL (IC_RESULT (ic))->iaccess)
2087 /* the operation has only one symbol
2088 operator then we can pack */
2089 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
2090 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
2093 if (!((IC_LEFT (dic) &&
2094 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
2096 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
2100 /* found the definition */
2101 /* replace the result with the result of */
2102 /* this assignment and remove this assignment */
2103 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2105 IC_RESULT (dic) = IC_RESULT (ic);
2107 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
2109 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
2111 /* delete from liverange table also
2112 delete from all the points inbetween and the new
2114 for (sic = dic; sic != ic; sic = sic->next)
2116 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
2117 if (IS_ITEMP (IC_RESULT (dic)))
2118 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
2121 remiCodeFromeBBlock (ebp, ic);
2122 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2123 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2124 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2129 /*-----------------------------------------------------------------*/
2130 /* findAssignToSym : scanning backwards looks for first assig found */
2131 /*-----------------------------------------------------------------*/
2133 findAssignToSym (operand * op, iCode * ic)
2137 for (dic = ic->prev; dic; dic = dic->prev)
2140 /* if definition by assignment */
2141 if (dic->op == '=' &&
2142 !POINTER_SET (dic) &&
2143 IC_RESULT (dic)->key == op->key
2144 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
2148 /* we are interested only if defined in far space */
2149 /* or in stack space in case of + & - */
2151 /* if assigned to a non-symbol then return
2153 if (!IS_SYMOP (IC_RIGHT (dic)))
2156 /* if the symbol is in far space then
2158 if (isOperandInFarSpace (IC_RIGHT (dic)))
2161 /* for + & - operations make sure that
2162 if it is on the stack it is the same
2163 as one of the three operands */
2164 if ((ic->op == '+' || ic->op == '-') &&
2165 OP_SYMBOL (IC_RIGHT (dic))->onStack)
2168 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
2169 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
2170 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
2178 /* if we find an usage then we cannot delete it */
2179 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
2182 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
2185 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
2189 /* now make sure that the right side of dic
2190 is not defined between ic & dic */
2193 iCode *sic = dic->next;
2195 for (; sic != ic; sic = sic->next)
2196 if (IC_RESULT (sic) &&
2197 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
2206 /*-----------------------------------------------------------------*/
2207 /* packRegsForSupport :- reduce some registers for support calls */
2208 /*-----------------------------------------------------------------*/
2210 packRegsForSupport (iCode * ic, eBBlock * ebp)
2214 /* for the left & right operand :- look to see if the
2215 left was assigned a true symbol in far space in that
2216 case replace them */
2217 if (IS_ITEMP (IC_LEFT (ic)) &&
2218 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2220 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
2226 /* found it we need to remove it from the
2228 for (sic = dic; sic != ic; sic = sic->next) {
2229 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
2230 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
2233 wassert(IS_SYMOP(IC_LEFT (ic)));
2234 wassert(IS_SYMOP(IC_RIGHT (dic)));
2235 IC_LEFT (ic)->operand.symOperand =
2236 IC_RIGHT (dic)->operand.symOperand;
2237 OP_SYMBOL(IC_LEFT(ic))->liveTo = ic->seq;
2238 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
2239 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2240 remiCodeFromeBBlock (ebp, dic);
2241 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2245 /* do the same for the right operand */
2248 IS_ITEMP (IC_RIGHT (ic)) &&
2249 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2251 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2257 /* if this is a subtraction & the result
2258 is a true symbol in far space then don't pack */
2259 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2261 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2262 if (IN_FARSPACE (SPEC_OCLS (etype)))
2265 /* found it we need to remove it from the
2267 for (sic = dic; sic != ic; sic = sic->next) {
2268 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
2269 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
2272 wassert(IS_SYMOP(IC_RIGHT (ic)));
2273 wassert(IS_SYMOP(IC_RIGHT (dic)));
2274 IC_RIGHT (ic)->operand.symOperand =
2275 IC_RIGHT (dic)->operand.symOperand;
2276 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
2277 OP_SYMBOL(IC_RIGHT(ic))->liveTo = ic->seq;
2278 remiCodeFromeBBlock (ebp, dic);
2279 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2280 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2287 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2290 /*-----------------------------------------------------------------*/
2291 /* packRegsDPTRnuse - color live ranges that can go into extra DPTRS */
2292 /*-----------------------------------------------------------------*/
2293 static int packRegsDPTRnuse( operand *op , int dptr)
2298 if (!IS_SYMOP(op) || !IS_ITEMP(op)) return 0;
2299 if (OP_SYMBOL(op)->remat || OP_SYMBOL(op)->ruonly || OP_SYMBOL(op)->dptr)
2302 /* first check if any overlapping liverange has already been
2303 assigned to this DPTR */
2304 if (OP_SYMBOL(op)->clashes) {
2305 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ ) {
2307 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i)) {
2308 sym = hTabItemWithKey(liveRanges,i);
2309 if (sym->dptr == dptr) return 0;
2314 /* future for more dptrs */
2316 OP_SYMBOL(op)->dptr = dptr;
2320 /* DPTR1 is special since it is also used as a scratch by the backend .
2321 so we walk thru the entire live range of this operand and make sure
2322 DPTR1 will not be used by the backed . The logic here is to find out if
2323 more than one operand in an icode is in far space then we give up : we
2324 don't keep it live across functions for now
2327 ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2328 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2329 ic = hTabNextItem(iCodeSeqhTab,&key)) {
2332 if (ic->op == CALL || ic->op == PCALL) return 0;
2334 /* single operand icode are ok */
2335 if (ic->op == IFX || ic->op == IPUSH)
2338 if (ic->op == SEND ) {
2339 if (ic->argreg != 1 ) return 0;
2342 /* two special cases first */
2343 if (POINTER_GET(ic) && !isOperandEqual(IC_LEFT(ic),op) && /* pointer get */
2344 !OP_SYMBOL(IC_LEFT(ic))->ruonly && /* with result in far space */
2345 (isOperandInFarSpace(IC_RESULT(ic)) &&
2346 !isOperandInReg(IC_RESULT(ic)))) {
2350 if (POINTER_SET(ic) && !isOperandEqual(IC_RESULT(ic),op) && /* pointer set */
2351 !OP_SYMBOL(IC_RESULT(ic))->ruonly && /* with right in far space */
2352 (isOperandInFarSpace(IC_RIGHT(ic)) &&
2353 !isOperandInReg(IC_RIGHT(ic)))) {
2357 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) && /* if symbol operand */
2358 !isOperandEqual(IC_RESULT(ic),op) && /* not the same as this */
2359 ((isOperandInFarSpace(IC_RESULT(ic)) || /* in farspace or */
2360 OP_SYMBOL(IC_RESULT(ic))->onStack) && /* on the stack */
2361 !isOperandInReg(IC_RESULT(ic)))) { /* and not in register */
2365 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) && /* if symbol operand */
2366 !isOperandEqual(IC_LEFT(ic),op) && /* not the same as this */
2367 ((isOperandInFarSpace(IC_LEFT(ic)) || /* in farspace or */
2368 OP_SYMBOL(IC_LEFT(ic))->onStack) && /* on the stack */
2369 !isOperandInReg(IC_LEFT(ic)))) { /* and not in register */
2372 /* same for right */
2373 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) && /* if symbol operand */
2374 !isOperandEqual(IC_RIGHT(ic),op) && /* not the same as this */
2375 ((isOperandInFarSpace(IC_RIGHT(ic)) || /* in farspace or */
2376 OP_SYMBOL(IC_RIGHT(ic))->onStack) && /* on the stack */
2377 !isOperandInReg(IC_RIGHT(ic)))) { /* and not in register */
2381 // Check that no other ops in this range have been assigned to dptr1.
2382 // I don't understand why this is not caught by the first check, above.
2383 // But it isn't always, see bug 769624.
2384 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2385 (OP_SYMBOL(IC_RESULT(ic))->dptr == 1))
2387 //fprintf(stderr, "dptr1 already in use in live range #1\n");
2391 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2392 (OP_SYMBOL(IC_LEFT(ic))->dptr == 1))
2394 //fprintf(stderr, "dptr1 already in use in live range # 2\n");
2398 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2399 (OP_SYMBOL(IC_RIGHT(ic))->dptr == 1))
2401 //fprintf(stderr, "dptr1 already in use in live range # 3\n");
2405 if (nfs && IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2406 OP_SYMBOL(IC_RESULT(ic))->ruonly) return 0;
2408 if (nfs > 1) return 0;
2410 OP_SYMBOL(op)->dptr = dptr;
2414 /*-----------------------------------------------------------------*/
2415 /* packRegsDPTRuse : - will reduce some registers for single Use */
2416 /*-----------------------------------------------------------------*/
2418 packRegsDPTRuse (operand * op)
2420 /* go thru entire liveRange of this variable & check for
2421 other possible usage of DPTR , if we don't find it the
2422 assign this to DPTR (ruonly)
2427 sym_link *type, *etype;
2429 if (!IS_SYMOP(op) || !IS_ITEMP(op)) return NULL;
2430 if (OP_SYMBOL(op)->remat || OP_SYMBOL(op)->ruonly) return NULL;
2432 /* first check if any overlapping liverange has already been
2434 if (OP_SYMBOL(op)->clashes) {
2435 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ ) {
2436 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i)) {
2437 sym = hTabItemWithKey(liveRanges,i);
2438 if (sym->ruonly) return NULL ;
2443 /* no then go thru this guys live range */
2444 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2445 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2446 ic = hTabNextItem(iCodeSeqhTab,&key)) {
2448 if (SKIP_IC3(ic)) continue;
2450 /* if PCALL cannot be sure give up */
2451 if (ic->op == PCALL) return NULL;
2453 /* if SEND & not the first parameter then giveup */
2454 if (ic->op == SEND && ic->argreg != 1 &&
2455 ((isOperandInFarSpace(IC_LEFT(ic)) && !isOperandInReg(IC_LEFT(ic))) ||
2456 isOperandEqual(op,IC_LEFT(ic)))) return NULL;
2458 /* if CALL then make sure it is VOID || return value not used
2459 or the return value is assigned to this one */
2460 if (ic->op == CALL) {
2461 if (OP_SYMBOL(IC_RESULT(ic))->liveTo ==
2462 OP_SYMBOL(IC_RESULT(ic))->liveFrom) continue ;
2463 etype = getSpec(type = operandType(IC_RESULT(ic)));
2464 if (getSize(type) == 0 || isOperandEqual(op,IC_RESULT(ic)))
2469 /* special case of add with a [remat] */
2470 if (ic->op == '+' &&
2471 OP_SYMBOL(IC_LEFT(ic))->remat &&
2472 (isOperandInFarSpace(IC_RIGHT(ic)) &&
2473 !isOperandInReg(IC_RIGHT(ic)))) return NULL ;
2477 if (POINTER_GET(ic) && !isOperandEqual(IC_LEFT(ic),op) &&
2478 getSize(operandType(IC_LEFT(ic))) > 1 ) return NULL ;
2481 if (POINTER_SET(ic) && !isOperandEqual(IC_RESULT(ic),op) &&
2482 getSize(operandType(IC_RESULT(ic))) > 1 ) return NULL;
2484 /* conditionals can destroy 'b' - make sure B wont
2485 be used in this one*/
2486 if ((IS_CONDITIONAL(ic) || ic->op == '*' || ic->op == '/' ||
2487 ic->op == LEFT_OP || ic->op == RIGHT_OP ) &&
2488 getSize(operandType(op)) > 3) return NULL;
2490 /* if this is a cast to a bigger type */
2492 if (!IS_PTR(OP_SYM_TYPE(IC_RESULT(ic))) &&
2493 getSize(OP_SYM_TYPE(IC_RESULT(ic))) >
2494 getSize(OP_SYM_TYPE(IC_RIGHT(ic)))) {
2500 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2501 !isOperandEqual(IC_RESULT(ic),op) &&
2502 ( ( ( isOperandInFarSpace(IC_RESULT(ic)) || OP_SYMBOL(IC_RESULT(ic))->onStack) &&
2503 !isOperandInReg(IC_RESULT(ic))) ||
2504 OP_SYMBOL(IC_RESULT(ic))->ruonly)) return NULL;
2506 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2507 !isOperandEqual(IC_RIGHT(ic),op) &&
2508 (OP_SYMBOL(IC_RIGHT(ic))->liveTo >= ic->seq ||
2509 IS_TRUE_SYMOP(IC_RIGHT(ic)) ||
2510 OP_SYMBOL(IC_RIGHT(ic))->ruonly) &&
2511 ( ( isOperandInFarSpace(IC_RIGHT(ic)) || OP_SYMBOL(IC_RIGHT(ic))->onStack) &&
2512 !isOperandInReg(IC_RIGHT(ic))) ) return NULL;
2514 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2515 !isOperandEqual(IC_LEFT(ic),op) &&
2516 (OP_SYMBOL(IC_LEFT(ic))->liveTo >= ic->seq ||
2517 IS_TRUE_SYMOP(IC_LEFT(ic)) ||
2518 OP_SYMBOL(IC_LEFT(ic))->ruonly) &&
2519 ( ( isOperandInFarSpace(IC_LEFT(ic)) || OP_SYMBOL(IC_LEFT(ic))->onStack) &&
2520 !isOperandInReg(IC_LEFT(ic))) ) return NULL;
2522 if (IC_LEFT(ic) && IC_RIGHT(ic) &&
2523 IS_ITEMP(IC_LEFT(ic)) && IS_ITEMP(IC_RIGHT(ic)) &&
2524 (isOperandInFarSpace(IC_LEFT(ic)) && !isOperandInReg(IC_LEFT(ic))) &&
2525 (isOperandInFarSpace(IC_RIGHT(ic)) && !isOperandInReg(IC_RIGHT(ic))))
2528 OP_SYMBOL(op)->ruonly = 1;
2529 if (OP_SYMBOL(op)->usl.spillLoc) {
2530 if (OP_SYMBOL(op)->spillA)
2531 OP_SYMBOL(op)->usl.spillLoc->allocreq--;
2532 OP_SYMBOL(op)->usl.spillLoc = NULL;
2537 /*-----------------------------------------------------------------*/
2538 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2539 /*-----------------------------------------------------------------*/
2541 isBitwiseOptimizable (iCode * ic)
2543 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2544 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2546 /* bitwise operations are considered optimizable
2547 under the following conditions (Jean-Louis VERN)
2559 if ( IS_LITERAL (rtype) ||
2560 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2566 /*-----------------------------------------------------------------*/
2567 /* packRegsForAccUse - pack registers for acc use */
2568 /*-----------------------------------------------------------------*/
2570 packRegsForAccUse (iCode * ic)
2574 /* if this is an aggregate, e.g. a one byte char array */
2575 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2579 /* if we are calling a reentrant function that has stack parameters */
2580 if (ic->op == CALL &&
2581 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2582 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2585 if (ic->op == PCALL &&
2586 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2587 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2590 /* if + or - then it has to be one byte result */
2591 if ((ic->op == '+' || ic->op == '-')
2592 && getSize (operandType (IC_RESULT (ic))) > 1)
2595 /* if shift operation make sure right side is not a literal */
2596 if (ic->op == RIGHT_OP &&
2597 (isOperandLiteral (IC_RIGHT (ic)) ||
2598 getSize (operandType (IC_RESULT (ic))) > 1))
2601 if (ic->op == LEFT_OP &&
2602 (isOperandLiteral (IC_RIGHT (ic)) ||
2603 getSize (operandType (IC_RESULT (ic))) > 1))
2606 if (IS_BITWISE_OP (ic) &&
2607 getSize (operandType (IC_RESULT (ic))) > 1)
2611 /* has only one definition */
2612 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2615 /* has only one use */
2616 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2619 /* and the usage immediately follows this iCode */
2620 if (!(uic = hTabItemWithKey (iCodehTab,
2621 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2624 if (ic->next != uic)
2627 /* if it is a conditional branch then we definitely can */
2631 if (uic->op == JUMPTABLE)
2634 /* if the usage is not is an assignment
2635 or an arithmetic / bitwise / shift operation then not */
2636 if (POINTER_SET (uic) &&
2637 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2640 if (uic->op != '=' &&
2641 !IS_ARITHMETIC_OP (uic) &&
2642 !IS_BITWISE_OP (uic) &&
2643 uic->op != LEFT_OP &&
2644 uic->op != RIGHT_OP)
2647 /* if used in ^ operation then make sure right is not a
2649 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2652 /* if shift operation make sure right side is not a literal */
2653 if (uic->op == RIGHT_OP &&
2654 (isOperandLiteral (IC_RIGHT (uic)) ||
2655 getSize (operandType (IC_RESULT (uic))) > 1))
2658 if (uic->op == LEFT_OP &&
2659 (isOperandLiteral (IC_RIGHT (uic)) ||
2660 getSize (operandType (IC_RESULT (uic))) > 1))
2663 /* make sure that the result of this icode is not on the
2664 stack, since acc is used to compute stack offset */
2665 if (isOperandOnStack(IC_RESULT(uic)))
2668 /* if either one of them in far space then we cannot */
2669 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2670 isOperandInFarSpace (IC_LEFT (uic))) ||
2671 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2672 isOperandInFarSpace (IC_RIGHT (uic))))
2675 /* if the usage has only one operand then we can */
2676 if (IC_LEFT (uic) == NULL ||
2677 IC_RIGHT (uic) == NULL)
2680 /* make sure this is on the left side if not
2681 a '+' since '+' is commutative */
2682 if (ic->op != '+' &&
2683 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2686 /* if the other one is not on stack then we can */
2687 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2688 (IS_ITEMP (IC_RIGHT (uic)) ||
2689 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2690 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2693 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2694 (IS_ITEMP (IC_LEFT (uic)) ||
2695 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2696 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2702 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2707 /*-----------------------------------------------------------------*/
2708 /* packForPush - hueristics to reduce iCode for pushing */
2709 /*-----------------------------------------------------------------*/
2711 packForPush (iCode * ic, eBBlock * ebp)
2716 if ((ic->op != IPUSH && ic->op != SEND) || !IS_ITEMP (IC_LEFT (ic)))
2719 /* must have only definition & one usage */
2720 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2721 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2724 /* find the definition */
2725 if (!(dic = hTabItemWithKey (iCodehTab,
2726 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2729 if (dic->op != '=' || POINTER_SET (dic))
2732 if (dic->eBBlockNum != ic->eBBlockNum) return ;
2734 /* make sure the right side does not have any definitions
2736 dbv = OP_DEFS(IC_RIGHT(dic));
2737 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2738 if (bitVectBitValue(dbv,lic->key)) return ;
2740 /* make sure they have the same type */
2741 if (IS_SPEC(operandType(IC_LEFT(ic))))
2743 sym_link *itype=operandType(IC_LEFT(ic));
2744 sym_link *ditype=operandType(IC_RIGHT(dic));
2746 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2747 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2750 /* extend the live range of replaced operand if needed */
2751 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < OP_SYMBOL(IC_LEFT(ic))->liveTo) {
2752 OP_SYMBOL(IC_RIGHT(dic))->liveTo = OP_SYMBOL(IC_LEFT(ic))->liveTo;
2753 OP_SYMBOL(IC_RIGHT(dic))->clashes =
2754 bitVectUnion(OP_SYMBOL(IC_RIGHT(dic))->clashes,
2755 OP_SYMBOL(IC_LEFT(ic))->clashes);
2757 for (lic = ic; lic && lic != dic; lic = lic->prev)
2759 bitVectUnSetBit (lic->rlive, IC_LEFT (ic)->key);
2760 if (IS_ITEMP (IC_RIGHT (dic)))
2761 bitVectSetBit (lic->rlive, IC_RIGHT (dic)->key);
2763 /* we now we know that it has one & only one def & use
2764 and the that the definition is an assignment */
2765 IC_LEFT (ic) = IC_RIGHT (dic);
2767 remiCodeFromeBBlock (ebp, dic);
2768 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2769 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2772 /*-----------------------------------------------------------------*/
2773 /* packRegisters - does some transformations to reduce register */
2775 /*-----------------------------------------------------------------*/
2777 packRegisters (eBBlock * ebp)
2787 /* look for assignments of the form */
2788 /* iTempNN = TRueSym (someoperation) SomeOperand */
2790 /* TrueSym := iTempNN:1 */
2791 for (ic = ebp->sch; ic; ic = ic->next)
2795 /* find assignment of the form TrueSym := iTempNN:1 */
2796 if (ic->op == '=' && !POINTER_SET (ic))
2797 change += packRegsForAssign (ic, ebp);
2804 for (ic = ebp->sch; ic; ic = ic->next)
2807 /* if this is an itemp & result of a address of a true sym
2808 then mark this as rematerialisable */
2809 if (ic->op == ADDRESS_OF &&
2810 IS_ITEMP (IC_RESULT (ic)) &&
2811 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2812 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2813 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2816 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2817 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2818 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2822 /* if this is an itemp & used as a pointer
2823 & assigned to a literal then remat */
2824 if (IS_ASSIGN_ICODE(ic) &&
2825 IS_ITEMP(IC_RESULT(ic)) &&
2826 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2827 isOperandLiteral(IC_RIGHT(ic)))
2829 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2830 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2831 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2834 /* if straight assignment then carry remat flag if
2835 this is the only definition */
2836 if (ic->op == '=' &&
2837 !POINTER_SET (ic) &&
2838 IS_SYMOP (IC_RIGHT (ic)) &&
2839 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2840 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2841 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2844 OP_SYMBOL (IC_RESULT (ic))->remat =
2845 OP_SYMBOL (IC_RIGHT (ic))->remat;
2846 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2847 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2850 /* if cast to a generic pointer & the pointer being
2851 cast is remat, then we can remat this cast as well */
2852 if (ic->op == CAST &&
2853 IS_SYMOP(IC_RIGHT(ic)) &&
2854 !OP_SYMBOL(IC_RESULT(ic))->isreqv &&
2855 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2856 sym_link *to_type = operandType(IC_LEFT(ic));
2857 sym_link *from_type = operandType(IC_RIGHT(ic));
2858 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2859 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2860 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2861 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2865 /* if this is a +/- operation with a rematerizable
2866 then mark this as rematerializable as well */
2867 if ((ic->op == '+' || ic->op == '-') &&
2868 (IS_SYMOP (IC_LEFT (ic)) &&
2869 IS_ITEMP (IC_RESULT (ic)) &&
2870 OP_SYMBOL (IC_LEFT (ic))->remat &&
2871 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2872 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2873 IS_OP_LITERAL (IC_RIGHT (ic))))
2876 //int i = operandLitValue(IC_RIGHT(ic));
2877 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2878 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2879 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2882 /* mark the pointer usages */
2883 if (POINTER_SET (ic) && IS_SYMOP (IC_RESULT (ic)))
2884 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2886 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic)))
2887 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2889 if (ic->op == RETURN && IS_SYMOP (IC_LEFT(ic)))
2890 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2892 if (ic->op == RECEIVE && ic->argreg == 1 &&
2893 IS_SYMOP (IC_RESULT (ic)) &&
2894 getSize (operandType(IC_RESULT(ic))) <= 3)
2895 OP_SYMBOL (IC_RESULT(ic))->uptr = 1;
2897 if (ic->op == SEND && ic->argreg == 1 &&
2898 IS_SYMOP(IC_LEFT(ic)) &&
2899 getSize (aggrToPtr(operandType(IC_LEFT(ic)),FALSE)) <= 3)
2900 OP_SYMBOL (IC_LEFT(ic))->uptr = 1;
2904 /* if we are using a symbol on the stack
2905 then we should say ds390_ptrRegReq */
2906 if (options.useXstack && ic->parmPush
2907 && (ic->op == IPUSH || ic->op == IPOP))
2909 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2910 ds390_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ? !options.stack10bit : 0) +
2911 OP_SYMBOL (IC_COND (ic))->iaccess +
2912 (SPEC_OCLS(OP_SYMBOL (IC_COND (ic))->etype) == idata));
2913 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2914 ds390_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ? !options.stack10bit : 0) +
2915 OP_SYMBOL (IC_JTCOND (ic))->iaccess +
2916 (SPEC_OCLS(OP_SYMBOL (IC_JTCOND (ic))->etype) == idata));
2919 if (IS_SYMOP (IC_LEFT (ic)))
2920 ds390_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ? !options.stack10bit : 0) +
2921 OP_SYMBOL (IC_LEFT (ic))->iaccess +
2922 (SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata));
2923 if (IS_SYMOP (IC_RIGHT (ic)))
2924 ds390_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ? !options.stack10bit : 0) +
2925 OP_SYMBOL (IC_RIGHT (ic))->iaccess +
2926 (SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata));
2927 if (IS_SYMOP (IC_RESULT (ic)))
2928 ds390_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ? !options.stack10bit : 0) +
2929 OP_SYMBOL (IC_RESULT (ic))->iaccess +
2930 (SPEC_OCLS(OP_SYMBOL (IC_RESULT (ic))->etype) == idata));
2934 /* if the condition of an if instruction
2935 is defined in the previous instruction and
2936 this is the only usage then
2937 mark the itemp as a conditional */
2938 if ((IS_CONDITIONAL (ic) ||
2939 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2940 ic->next && ic->next->op == IFX &&
2941 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2942 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2943 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2945 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2949 /* reduce for support function calls */
2950 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2951 packRegsForSupport (ic, ebp);
2953 /* some cases the redundant moves can
2954 can be eliminated for return statements . Can be elminated for the first SEND */
2955 if ((ic->op == RETURN ||
2956 ((ic->op == SEND || ic->op == RECEIVE)&& ic->argreg == 1)) &&
2957 !isOperandInFarSpace (IC_LEFT (ic)) &&
2960 packRegsDPTRuse (IC_LEFT (ic));
2963 if (ic->op == CALL) {
2964 sym_link *ftype = operandType(IC_LEFT(ic));
2965 if (getSize(operandType(IC_RESULT(ic))) <= 4 &&
2966 !IFFUNC_ISBUILTIN(ftype)) {
2967 packRegsDPTRuse (IC_RESULT (ic));
2971 /* if pointer set & left has a size more than
2972 one and right is not in far space */
2973 if (POINTER_SET (ic) &&
2974 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2975 IS_SYMOP (IC_RESULT (ic)) &&
2976 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2977 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2978 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1) {
2980 packRegsDPTRuse (IC_RESULT (ic));
2983 /* if pointer get */
2984 if (POINTER_GET (ic) &&
2985 !isOperandInFarSpace (IC_RESULT (ic)) &&
2986 IS_SYMOP (IC_LEFT (ic)) &&
2987 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2988 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2989 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1) {
2991 packRegsDPTRuse (IC_LEFT (ic));
2994 /* if this is cast for intergral promotion then
2995 check if only use of the definition of the
2996 operand being casted/ if yes then replace
2997 the result of that arithmetic operation with
2998 this result and get rid of the cast */
3001 sym_link *fromType = operandType (IC_RIGHT (ic));
3002 sym_link *toType = operandType (IC_LEFT (ic));
3004 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
3005 getSize (fromType) != getSize (toType) &&
3006 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
3009 iCode *dic = packRegsDPTRuse (IC_RIGHT (ic));
3012 if (IS_ARITHMETIC_OP (dic))
3014 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
3015 IC_RESULT (dic) = IC_RESULT (ic);
3016 remiCodeFromeBBlock (ebp, ic);
3017 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3018 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3019 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3023 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
3029 /* if the type from and type to are the same
3030 then if this is the only use then packit */
3031 if (compareType (operandType (IC_RIGHT (ic)),
3032 operandType (IC_LEFT (ic))) == 1)
3034 iCode *dic = packRegsDPTRuse (IC_RIGHT (ic));
3037 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3038 IC_RESULT (dic) = IC_RESULT (ic);
3039 remiCodeFromeBBlock (ebp, ic);
3040 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3041 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3042 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3050 iTempNN := (some variable in farspace) V1
3055 if (ic->op == IPUSH || ic->op == SEND)
3057 packForPush (ic, ebp);
3061 /* pack registers for accumulator use, when the
3062 result of an arithmetic or bit wise operation
3063 has only one use, that use is immediately following
3064 the defintion and the using iCode has only one
3065 operand or has two operands but one is literal &
3066 the result of that operation is not on stack then
3067 we can leave the result of this operation in acc:b
3069 if ((IS_ARITHMETIC_OP (ic)
3070 || IS_CONDITIONAL(ic)
3071 || IS_BITWISE_OP (ic)
3072 || ic->op == LEFT_OP || ic->op == RIGHT_OP
3073 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
3075 IS_ITEMP (IC_RESULT (ic)) &&
3076 getSize (operandType (IC_RESULT (ic))) <= 2)
3078 packRegsForAccUse (ic);
3083 /*-----------------------------------------------------------------*/
3084 /* assignRegisters - assigns registers to each live range as need */
3085 /*-----------------------------------------------------------------*/
3087 ds390_assignRegisters (eBBlock ** ebbs, int count)
3092 setToNull ((void *) &_G.funcrUsed);
3093 setToNull ((void *) &_G.regAssigned);
3094 setToNull ((void *) &_G.totRegAssigned);
3095 setToNull ((void *) &_G.funcrUsed);
3096 ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
3098 if (options.model != MODEL_FLAT24) options.stack10bit = 0;
3099 /* change assignments this will remove some
3100 live ranges reducing some register pressure */
3101 for (i = 0; i < count; i++)
3102 packRegisters (ebbs[i]);
3104 /* liveranges probably changed by register packing
3105 so we compute them again */
3106 recomputeLiveRanges (ebbs, count);
3108 if (options.dump_pack)
3109 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3111 /* first determine for each live range the number of
3112 registers & the type of registers required for each */
3115 /* and serially allocate registers */
3116 serialRegAssign (ebbs, count);
3123 /* if stack was extended then tell the user */
3126 /* werror(W_TOOMANY_SPILS,"stack", */
3127 /* _G.stackExtend,currFunc->name,""); */
3133 /* werror(W_TOOMANY_SPILS,"data space", */
3134 /* _G.dataExtend,currFunc->name,""); */
3138 /* after that create the register mask
3139 for each of the instruction */
3140 createRegMask (ebbs, count);
3142 /* redo that offsets for stacked automatic variables */
3144 redoStackOffsets ();
3146 /* make sure r0 & r1 are flagged as used if they might be used */
3148 if (currFunc && ds390_ptrRegReq)
3150 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R0_IDX);
3151 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R1_IDX);
3154 if (options.dump_rassgn) {
3155 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3156 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3159 /* do the overlaysegment stuff SDCCmem.c */
3160 doOverlays (ebbs, count);
3162 /* now get back the chain */
3163 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3168 /* free up any _G.stackSpil locations allocated */
3169 applyToSet (_G.stackSpil, deallocStackSpil);
3171 setToNull ((void *) &_G.stackSpil);
3172 setToNull ((void *) &_G.spiltSet);
3173 /* mark all registers as free */